87
Climbing Hills
Figure 7 shows the concept of climbing a hill , and the forces acting on
the three wheeler as a result .
The weight forces remain constant , but they
act in a line closer to the point of support A .
The inertia forces F depend on the acceleration . In units of " g " ,
standard acceleration of gravity , and for different hill slopes , the chart at
the bottom summarizes the results . To appreciate the fact that the
acceleration values are modest , an acceleration of 0 . 3g corresponds to about
10 feet / second / second . This is equivalent to attaining a speed of about 20
mph in 3 seconds , after traveling a distance of about 45 feet . ( It is , of
course , not necessary to travel the 45 feet ; it is sufficient to attain the
requisite acceleration ) .
Other Problems
I believe that the foregoing is sufficiently illustrative of the
possibilities . A complete analysis would include such matters as frame
deformation , the possibility of resonance in the system , and other items . As a
matter of interest , the Mckinley case involved a combination of riding on a
side slope and a sudden change in terrain requiring a turn .